Control device for change-speed gears



Jan. 7, 1941,

E. DAUSCH ETAL CONTROL DEVICE FOR CHANGE-SPEED GEARS Filed April 5, 19383 Sheets-Sheet 1 Jan. 7, 1941. 5, H' HAL 2,227,879

CONTROL DEVICE FOR CHANGE-SPEED GEARS Filed April 5, 1958 3 Sheets-Sheet2 12w QMM 311 ,1 E. DAUSCH E'l'AL 2,227,879 CONTROL DEVICE FORcrpmGE-sPEEn GEARS I Filed April 5, 1938 3 Sheets-Sheet 3 35 one of theclutch members.

Patented Jan. 7, 1941 UNITED STATES PATENT OFFICE 2,227,879 CONTROLDEVICE FOR CHAN GE-SPEED GEARS Erwin Dausch and Gustav Meyer,Friedrichshafen-on-the-Bodensee, Germany, assignors toMaybach-Motorenbau Gesellschaft mit beschrankter Haftung,Friedrichshafen-on-the- Bodensee, Germany, a corporation of GermanyApplication April 5, 1938, Serial No. 200,252 In Germany July 17, 193712 Claims. (01. 74-364) The invention relates to a control device for anauxiliary power device for operating changespeed gears, in which inchanging the speed ratios, it is necessary to change a plurality oftransmission stages, in particular for motor vehicles. It is employedprincipally in changespeed gears having a large number of speed ratios,for example six-speed gears or gears with more speeds, in particular ingears wherein at l0 least two transmission stages are changedalternately by means of change-speed clutches, for example dog clutches,if desired without assuming a central position. Such gears are employedabove all in cases where it is desired that the gear-changing operationshould proceed rapidly,

that is to say, the gear-changing time has to be reduced to a minimum.This purpose is served to some extent by special accelerating andretarding devices of known kind for one of the clutch members to beengaged. The invention may also be employed in gears wherein suchdevices are not provided.

The essential feature of the invention is .that

the control members controlling the auxiliary power, for example thepressure for the gearchanging cylinders of the transmission stages to bechanged, are combined in twogroups, one group serving for control-lingthe actuating members (gear-changing cylinders or gear-changing cylinderends) of the transmission stagm; requir- 40 trol, as fewer levers arerequired for the operation of the control cylinders. The arrangement ofthe conduits from the control cylinders to the actual gear-changingdevice is much clearer and simpler. In thecase of faults, theirlocalisation 45 is thereby considerabiy facilitated.

In a further development of the invention, each group of con-trolmembers is connected to an auxiliary power supply conduit, of which atleast one comprises a shut-off member whereby 'the re- 50 tardation andacceleration gear changes are prevented from proceeding simultaneously.This ensures the shortest gear-changing time employing a simple controldevice having only slight losses in the auxiliary power transmission,and in- 55 creases the reliability of operation of the control device.

A change-speed gear and two constructional examples of control devicestherefor according to the invention are shown diagrammatically and nolargely in section in the accompanying drawings.

In these examples, vacuum has been assumed as the operating power.

Figure 1 shows the change-speed gear which is adapted to be controlledby means embodying the principle of the present invention. Thischange-speed gearing, per se, is covered by the U. S. patent to Maybach,'No. 2,030,752, and the general type of gearing, of which this is anexample, is covered by the Maybach U. S. Patents,

Nos. 1,949,167 and 1,949,168. 10

Figure 2 relates to the first example, while Figures 3 and 4 showanother example differing from the first example by the fact thatindividual control members for the acceleration gear changes andlikewise the con-trol members form the retardation gear changes havebeen combined in respective groups, each having a common pressure mediumsupply conduit.

On the main shaft line of the change-speed gear shown in Figure 1 arethe gear wheels 1, 8, 20

9, I0 and on the lay shaft linethe gear wheels ll, l2, l3 and M. Thegear wheels I, 9, and I3 are fast on their corresponding shaft sectionsl, 2, 4 and 5, or 6, while gear Wheel I0 is freely rotatable on shaftsection 3 and gear wheel I! is 25 splined on shaft section 6. Gearwheels 1, 8, 9, H and I2 are mounted with their hubs I5 in the housingI6, gear wheels =8 and I2 having bores in which the adjacent shaftsections I and 2 or 4 and 5 are mounted.. Between the permanently 30meshed pairs of wheels 1/, 8/ l2 and 9/l3 are pairs of change-speed dogclutches l1, l8 and i9, 20, which in the present case, particularly forthe purpose of shortening the overall length, are

constructed in such a manner that the clutches l1 and W are in the mainshaft line and the corresponding clutches -I8 and .20, respectively,-are in the layshaft line. The gear changing lever 2| connecting theclutches ll and 1-8 together is,

secured to a shaft 22 and the gear-changing lever 23 for actuating theclutches I9 and 20 is secured to a shaft 2-4. In addition, on the shaftsection 3, is splined a double dog clutch 25, its teeth 25 being adaptedto be brought into engagement with corresponding dog teeth of the gearwheel 9, and its teeth 25" being adapted to be brought into engagementwith corresponding dog teeth on the gear wheel Ill. The gear-changinglever 26 for this change-speed dog clutch?! is fast on a shaft 21. Theclutch teeth of all the clutches (ll, l8; i9, 20; 25) are provided withbevelled end faces, .whereby engagement of the clutches is effected inknown manner at the moment of overtaking.

Mounted slidably on a further short lay-shaft is a'reversing drive 30,3|, the gear wheel 30 whereof can .be brought into engagement with thegear wheel l4, 'when the latter has been shiftedv to the left, and itsgear wheel 3| can be brought into engagement with the gear wheel l0. The1 I be-running more quickly and will therefore reselection of thereverse speed is effected by mechanical means which do not form part ofthe present invention and will therefore not be further described. I

The bevelling of the end faces of the dogs indicated in Figure 1corresponds to the direction of rotation shown at wheel '1 in Figure 1.Starting for example from the engagement of the 'clutch -I1 with theclutch member provided on gear wheel 8, as indicated in Figure 1, and ifin- I stead thereof the clutch I8 is to be brought into engagement withthe corresponding clutch member mounted on gear wheel I2, then when thedogs of clutch I8 are applied to-the dogs connected to gear .wheel I2,the latter dogs will first ject the dogs of clutch I8 (position ofrejection).

. If now, by opening the throttle, the driver'in creases the speed ofgear wheel 1 and hence also of gear wheel I I and of the clutch I8connected to shaft 4 of said gear wheel II, the clutch I8 will finallyovertake the counter-clutch member connected to gear wheel I2 and theengagement.

I of the clutch will be effected in known manner.

Engagement takes place in a similar manner whenclutch I8 is 'brought outof engagement and clutch I1 is engaged. In this case, the clutch memberconnected to gear wheel 8 is the more slowly running member. The dogs ofthe, at first, more rapidly running clutch I1,,which move past the-saidclutch member connected .to gear wheel 8 will be rejected until, due tothe diminishing speed of the engine resulting" from the driver closingthe throttle, their speed will also fall below that of the clutch memberconnected to gear wheel 8, engagement then taking place.

If the gear mechanism shown in Figure 1 per-.

mi-tting eight forward and four reverse speeds is employed asa sevenspeed gear, the following sequence of speeds may be obtained forexample, 29 teeth being provided for example on the gear wheel], 40teeth on gear (wheel 8, 35 on gear wheel 8,44 .on. gear wheel I0, 60 ongear II, 48

on gear wheel, 53 on gear wheel I3 and 22 teeth on gear wheel I4:

Forward I I. Shaft I, gear wheel 1, gear wheelll, shaft clutch I5, shaft2, gear wheel 5, gear wheel I3, shaft 8, gear wheel I4, gear .wheel !I0, clutch 25", shaft 2.

5,- gear wheel I3, shaft 8, ge'ar wheel I4, gear wheel 10, clutch -25",shaft 3.. 1

. Shaft I, clutch I1, gear wheel 8, clutch I9, shaft 2, gear wheel 8,gear wheel I3, 'shaft '8, gear wheel I4, gear wheel I0,- clutch 25".

.4, clutch I8, gear wheel I2, ge'ar wheel 8, clutch I5, shaft 2; gearwheel 8, clutch 25, shaft 2.

V: Shaft I, gear wheel 1, gear wheel II, shaft 4, clutch I8, gear wheelI2, clutch 20, shaft 5, gear wheel I3, gear wheel 'Ol.l1-tch 25', shaft3.

. Shaft I, clutch .I1, gear wheel 8, clutch shaft 2, gear wheel 5,clutch 25', shaft 3 (direct drive).

wheel 8. clutch25', shaft 8 (speed shown indrawings).

' tion or retardation gear change.

4, clutch I8, gear wheel I2, gear wheel 8,

. Shaft I, gear wheel 1, gear wheel II, shaft 4, clutch I8, gear wheelI2, clutch 28, shaft Shaft I, gear wheel 1, .gear wheel II, shaft ShaftI, clutch -I1, gear wheel 8, gear wheel I2, clutch 28, shaft 5, gearwheel I3, gear I A recerse drive is for example Shaft I, gear wheel 1,gear wheel II, shaft 4,

clutch I8, gear wheel I2, gear wheel 8, clutch' I8, shaft 2, gear wheel8, gear wheel I3, shaft -8, gear wheel I4, gear wheel 30, gear wheel 3|,gear wheel I0, clutch 25", shaft 3.

In Figure 2, 22, 24 and 21 again denote the gear-changing shafts of thegear-wheel changespeed gear shown in Figure 1. Mounted on saidgear-changing shafts are levers 35, 45 and 55 connected to which arepiston rods 38, 48 and 58,

the pistons whereof are arranged in cylinders 31, 41 and 51. Connectedto one end of these cylinders respectively are the conduits I39, I49 andI58, and at the other end the conduits I40, I50

and I80. The end positions of the pistons 38, v

48 and 58 are denoted by B or' V, according to whether the transfer ofthese pistons into the denoted position is accompanied by an acceleraFurthermore, I80 denotes a distributing valve controlling the conduitsI40, I50, I80; and 22 is a further distributing valve controlling theconduits I38, I49, I58. I80 is 'a shut-off valve which is moved by thepiston I8I acting through .the pin I82 and is held by a spring I83 inthe opened position against the surface I84. I85 is the seat of thevalve in the housing I88. I81 is a supply conduit for pressure mediumwhich in the present 'case. is-ccnnected to the induction pipe of the"grooves and bores in these valves are not-particularly shown in thedrawings.

. I5I and 'I8I are two shut-01f slide valves arranged in the-housing 2I0and are connected to the cylinders 31 and 41 by the conduits 201 and-208. 208 is a connecting conduit between-the cylinder 51 and the housing2I0. The pistons I5I and I8! have shortpassages 2H andj2l2 and alsoannular grooves 205 and 208:. v 204 is a connecting passage between thetwo guide bores for the pistons I5Iand -I'8I in'the housing-2H.

The piston rods 38, 48 and -58 are' provided with grooves 223, 224 and225. the cylinders 31, '41 and 51 guiding the piston rods are bores 2I3,2H and 2I'5 which are i communication with the outer air. I

The operation of. the control device shown in Figure 2 is as follows:

In the-drawings, the pistons of the Q'ear-chang ing cylinders are shownin the positions cor-respending to the; second. speed. The distributingvalves I 80 and 200 appropriately coupled together have been just set tothe position corresponding to the third speed. For changing over to 3rdspeed, the pistons38fand 48 must be moved to their left-hand .endposition, the transmission stage pertaining to the cylinder-'81 beingthereby In the extensions of engaged with retardation of one'member,

and the transmission stage. pertaining to the eviinder 41 being engagedwithaocelei'ation of one clutch member. The conduit I58 is connected bythe control groove I81 of the distributing valve.

In to the, passage III supplying the vacuum. At

' the same time, the controlgroove I58 of the distributing .valve 200connects the conduit I39 to the vacuum supply conduit I89. The vacuumacting through the conduit I39 on the piston 38 moves the latter out ofits right-hand end position still shown in the drawings at first so farto the left until the corresponding clutch member of the gear is in theposition of rejection at the counter-clutch member. Engagement does notyet take place since the driving clutch member is rotating more rapidlythan the counterclutch member.

In these positions, the vacuum existing on the left of the piston 38passesvia the groove 223 and conduit 201 to the housing 2I0 and drawsthe small valve I5I to the right. The bore 2 is thereby brought in frontof the connection of the conduit I92, while simultaneously the passage204 opposite is shut off. The vacuum supplied through the conduit 201now enters the conduit I92 and throughthe latter into the space on theleft in front of the small piston I8I. The piston I 8I isthereby movedto the left and the valve I80 is applied to the seat I85 against thepressure of the spring I83. The supply of vacuum from the conduit I81via the branch conduit I88 to the passage I9I is thereby interrupted.Although the conduit I50 is connected to the vacu-, um supply conduit bythe distributing valve I90, no vacuum can enter the conduit I50. Thepiston 48 therefore at first remains in its right-hand end position.

, If, due to the reduction in speed of the engine, the engagement speedof the clutch member moved by the piston 38 -has been attained, the saidclutch member is able to engage and the piston 38 is able to movecompletely into its lefthand end position, the right-hand edge of thegroove 223 first shutting off the supply of vacuum to said groove fromthe space on the left in front 40 of the piston 38. When the piston 38has moved completely into its left-hand end position, the conduit 201 isconnected by the groove 223 to the bore 2I3, through which the space onthe right of the piston valve I5I is now connected to the 45 outer airvia the conduit 201 and the groove 223.

The piston valve I5I is thereby returned intoits left-hand end position.The conduit I92 is thereby connected via the annular groove 205,

connecting passage 204 and the annular groove 50 208 as well as theconduit 209 and the groove 225 in the rod 58 of the piston 58 with thespace above the piston 58, and via the conduit I 59, corresponding bore221 in the valve 200, space above this valve and the bore 202 in thevalve housing 5 with the outer air. Due to the pressure of the outer airsupplied in this way via conduit I92 to the space on the left in frontof the piston I8I, the piston I8I is again returned into its righthandend position and the valve I80 is lifted off 80 its seat by the pressureof its spring I83.and is applied against the surface I84.

Vacuum is now able to pass from the conduit I88 via the passage I9I andcontrol groove I91 a in the distributing valve I90 to the conduit I50.65 The piston 48 is thereby drawn to the left,the clutch member actuatedby the latter is applied to the counter-clutch member where it isatfirst rejected on account of its higher speed. It comes intoengagement as soon as the overtaking speed has been attained by openingthe throttle, the piston 48 moving into its left-hand end position. Thegear changing operation is thus terminated.

In this gear-change, the groove 224 on the piston rod 48 does not exertany efiect on the valve 75 I8l, since the space to the right of thepiston '48 and hence also the conduit 208 in this gear change do nothave any vacuum supplied to them, but remain in communication with theouter air through the conduit I49, corresponding bore in thedistributing valve 200, space above said valve and the bore 202 in thevalve housing.

As will be'immediately appreciated from the drawings, if one of the twocylinders 31 or 41 is carrying out a retardation gear change andsimultaneously a gear change of cylinder 51 is adjusted by thedistributing valves I90 and 200, an acceleration gear change of thecylinder 51 is prevented, in the same way as described'above, by thevalves I5I 0r I8I by means of the main shut-ofi valve I80. Accelerationgear changes of the cylinders 31, 41, however, are also prevented whilethe cylinder 51 is performing a re-' tardation gear change. This iseffected by the fact that in the case of a retardation gear change ofthe cylinder 51," the vacuum supplied through the conduit 209 to thevalve I8I passes by way of the groove 208, passage 204, and groove 205into the conduit I92 and by moving the piston 'I8I to the left closesthe valve I80 upon its seat I85.

The form of construction of a device according to the invention as shownin Figures 3 and 4 is likewise suitable for the change-speed gear shownin Figure 1 and replaces the selector valve assembly shown in the lowerhalf of Figure 2. In this construction each of the six conduits leadingto the gear-changing cylinders is provided with a separate controlvalve. Figur 3 is a vertical section through the device and Figure 4 isa horizontal. section substantially along the plane of section A-A ofFigure 3. but in the lefthand top corner of Figure 4, the section istaken along the plane 3-3. The vertical section shown in Figure 3 issubstantially along the vertical plane represented by the line 0-0in-Figure 4, but in the left-hand part of Figure 3, -a section alongplane DD is also shown.

In Figures 3 and 4, 2, 242, 243, 244, 245 and 248 denote control valvesloaded by the springs 25], 252, 253, 254, 255 and 258, each valve whichis denoted by an odd number and the valve denoted by the following evennumber being moved by one of the levers 241, 248, 249. Said levers aremounted in the chamber 250 of the housing 280 and are actuated by meansof a'lever 259 through cam'discs mounted on the spindle 251. Figure 3shows the cam disc 258 for actuating the lever it is an elbow passage214 opening into the charm ber 215. Conduit 283 opens into the chamber218. I40, I50, I80, I39, I49 and I59 are control conduits connected tothe chambers 29I, 293, 295.

292, 294 and 298 situated behindthe valves 2,

243, 245, 242, 244 and 248 and leading to the cor- The lever at the end'of its lower part is a ball 281 sur- H rounded by a shoe 291. againstthe lower part of the lever 241. levers' 248 and 249 are constructedsimilarly.

The

A spring 3I1 presses l spherical lower end 281 of the lever, the shoe291 is thereby driven to the right and the valve 24l, which up to-thispoint has assumed the, opened position shown in Figure 3, is closed. Atthe same time, the shoe 291 comes in front of the left- 5 hand end ofthe valve 242, whereby the latter is opened. In this way, the supply ofvacuum to the right hand end of the cylinder 31 connected to the controlconduit I40 is closed, while the connection of the vacuum supply conduit263 via the chamber 216 with the conduit I39 and with'the left hand endof the cylinder 31 connected to the latter is opened.

Upon the actuation of the cam discs, according 4 30. change grouparranged on the right will be moved in the same way as described above,by means of the three levers 241, 248, 249. If it is not necessary todisengage or engage a transmission stage, the corresponding valvesremain in the openedor 35 closed position, respectively, due to the factthat r the nose of the corresponding lever in these cases remains eitheron a'groove of the corresponding cam disc, said groove extending overthe next division or on the periphery oi the corresponding 40 cam, saidperiphery extendingover the next cam division.

In the same way as is shown in the construction according .to Figure 2,the conduit I92 is conf trolled by the gear-changing pressure operative.

- in the cylinders in such a manner that in Figures 3 and 4, the valve264 corresponding to the valve I80 of Figure 2 is applied to its seat212 a the case of a retardation gear-change of ,one or the othercylinder. The supply of vacuum from the conduit 262 via valve 264,chamber 213 and 'elbow passage 214 to the common chamber 215 situated iniront of the valves 24], 243 and 245 is thereby shut off until theretardation gearchange concerned is terminated, and .the accelerationgear-change'of the one orthe other of the other cylinders can proceed.

We claim:

1. A- gear-shifting mechanism for a; gear:- wheel change-speed gearcomprising: a plurality I and each of said conduits, the control meansbeduitsleading to each of said devices for carryof power-operatedgear-shifting devices, two coning working medium thereto for operationin opposite directions to and-from two positions of adjustment, a sourceof working medium, and a control means between said source and each'ofsaid conduits, the control means -being arranged in two separate groups,each group comprising a control means pertaining to one of the positionsof adjustment of each of said power-operated gear-shifting devices.

-2. A gear-shifting mechanism for 'a -gearwheel change-speed gearcomprising: a plurality of power-operated gear-shifting devices, twoconduits leading to each of said devices for carrying 7g workingmediumthereto for operation in opposite.

directions to and from two positions of adjustmerit, a source of workingmedium, and a control means between said source and each of saidconduits, saidcontrol means each comprising a separate control memberand being arranged in two groups, each group comprising a control meanspertaining to each of said power-operated gear-, shifting devices.

3. A gear-shifting mechanism for a gearwheel change-speed gearcomprising: a plurality of power-operated gear-shifting devices, two

conduits leading .to each of said devices for car- I ranged in twogroups, each group comprisinga control means pertaining to each of saidpoweroperated gear-shifting devices, and two conduits, one common to thecontrol means of each group, for carrying working medium to said controlmeans. 1

4. A gear-shifting mechanism for a gear-wheel change-speed gearcomprising: a plurality of power-operated gear-shifting devices, twoconduits leading to each of said devices for carrying working mediumthereto for operation in opposite directions, a control means connectedto each of said conduits, said control means each comprising a separatecontrol member and being arranged in two groups, each group comprising acontrol means pertaining to each of said poweroperated gear-shiftingdevices, two conduits, one a 1 common to the'control means of eachgroup, for carrying working medium to'said control means, a shut-oildevice in one of said last-mentioned conduits, and means responsive toworking medium passing any of the control means connected to the otherof said last-mentioned conduits for actuating said shut-off device.

5. A transmission comprising in combination a gear-wheel change-speedgear of the kind having disengageable positive engaging gear-changemembers for efiecting changes oi. ratio, acceleration of the drivingshaft being necessary for the engagem'entoi some oisaid gear-changemembers and. retardation of thedriving shaft being necessary forthe'engagement 'of others, and in which the selection of at least one ofthe gear ratios requires the engagement of gear-change members.requiring acceleration and of gearchange members requiring retardation,and a gear-shitting mechanism comprising a plurality of power-operatedgear-shifting devices opera: tively connected'with said gear-changemembers, 'twoconduits leading to each of said devices for carryingworking medium thereto. for operation in opposite directions, a source'of working medium, and a control means between said source which eachcontrol means comprises a separately movable control' member..

"7. A transmissionas claimed in claim 5, in which each group of controlmeans comprises a conduit common to the group for carrying workingmedium thereto.

8. A transmission as claimed in claim 5, comprising a separately movablecontrol member for each control means, a conduit common to each group ofcontrol means for carrying working inc-'- dium thereto, a shut-offdevice in one of said common conduits, and means responsive to workingto conduits for carrying working medium,

to said gear-shifting devices for the operation thereof in the directionfor engaging gearchange members requiring acceleration of one of themembers to be engaged, and means responsive to working medium passingany of the a control means connected to the other of said commonconduitsfor actuating said shut-oi! de- 10. A gear-shitting mechanism foragearwheel change-speed gear comprising a plurality of power-operatedgear-shifting devices, two conduits leadingto each of said devices .forcarrying working medium thereto for operation in opposite directions, acontrolmeans connected to each 01' said conduits, the control meansbeingarranged in two groups, eachgroup comprising a control means. pertainingto each of said n as claimed in claim 5, com-,

power-operated gear-shifting devices, two conduits, one common to thecontrol mean; of each group, for carrying working medium to said controlmeans, a shut-oil! device in one of said last-- mentioned. conduits, andmeans responsive to working medium passing any of the contrc' meansconnected to the other of said last-mentionedconduits i'oractuating saidshut-oft device. v

11. A transmission as claimed in claim 5 in which there is provided aconduit common to each group of control means for carrying workingmedium thereto, a shut-oil device in one of said common conduits, andmeans responsive to working medium passing any of the control meansconnected toltheother of said common conduits for actuating saidshut-oil device.

12. A transmission as claimed in claim 5 in which there is provided aconduit common to each group of control means forcarrying working medium'thereto,a shut-oflf device in said 'conduit common to the group ofcontrol means pertaining to conduits for carrying working medium to saidgear-shifting devices for the operation thereof in the direction forengaging gearchange members requiring acceleration of one of thegmembersto be engaged, and means responsive to working medium passingany or thecontrol means connected to the other of said common conduits foractuating said shut-oil device,

' liiRWlLl DAUSCH.

GUSTAV MEYER.

